assume cs:codesg

codesg segment
	
	mov ax,2000h ;ax=2000
	mov ss,ax    ;ss=2000,ax=2000
	mov sp,0h    ;sp=0
	add sp,10h   ;sp=10
	pop ax       ;pop到ax(stack中为空),ax=0000,sp=0012.
	pop bx       ;bx =0000,sp=0014
	push ax      ;ax进,sp=0012,stack顶 = 0000
	push bx      ;bx=0000,stack=0000，sp=0010
	pop ax       ;
	pop bx

	mov ax,4c00h
	int 21h
codesg ends

end
